Discover the 5 most common application security vulnerabilities and related risks. In this guide, we’ll look at some popular application vulnerabilities from the OWASP Top 10 and discuss best practices & prevention tactics to fix issues and ensure cybersecurity.
<H2> What is Application Vulnerabilities
By application vulnerability, we mean design flaws in code or configuration that are susceptible to potential attacks, which can lead to sensitive data exposure. This typically results from mistakes at various stages of development, as well as insufficient security controls, allowing hackers to bypass authentication or inject malicious code.
Because unaddressed security risks can lead to breaches, application developers face significant financial losses and loss of trust. According to IBM, the global average cost of a data breach is $4.4 million. This means that robust application security posture management and a proactive approach to software security are critical for organizations. Threat modeling, application code reviews, secure frameworks, regular software updates, and a DevSecOps approach help identify gaps and significantly reduce risk.
By providing services to clients through an app or web application, organizations interact with and store sensitive data that is of interest to attackers. Even a single insecure component can become a gateway for exploitation, so the question of how to identify vulnerabilities effectively is paramount. Lack of reliable software security is a 100% guarantee of failure. Investing in application security reduces the risk of breaches, protects stored data, and ensures compliance with industry regulations. The good news is that common vulnerabilities can be fixed and prevented early on with the right development approach. Collaborating with a development firm is a way to implement strong application security strategies, thereby avoiding loss of money, time, and reputation for fintech companies.
<H2> 5 Key Vulnerabilities in Fintech Apps
The OWASP Top Ten list is especially valuable when it comes to current and new vulnerabilities. Although it includes 10 issues, five vulnerabilities are the most common. Therefore, promptly addressing them allows you to avoid most software security mistakes.
<H3> Insecure APIs and Broken Authentication
Weak authentication mechanisms allow an attacker to bypass login systems and gain unauthorized access to steal credentials or escalate privileges. Hackers can do this through URL rewriting, misconfigured application timeouts, poor password hashing, or predictable login credentials. Key factors to consider include implementing appropriate identity and access controls and avoiding the use of plain passwords. The PCI DSS standard now requires implementing multi-factor authentication as an application security control, which significantly minimizes the issue of broken authentication.
When it comes to APIs, it’s crucial to ensure their security, which can be achieved through implementing rate limiting and throttling, updating security controls (MFA, automatic time-based rotation), and continuous monitoring to detect abnormal API traffic.
(по інфографіці можна додати до кожної з vulnerabilities аналогічне зображення як на скріні. Текст для Insecure APIs and Broken Authentication — 95% of companies have experienced security problems in production APIs, with 23% having experienced a breach. Link: https://salt.security/blog/its-2024-and-the-api-breaches-keep-coming)
<H3> Injection Flaws
Common injection attacks include SQL injection and cross-site scripting (XSS). SQL injection occurs when a hacker inserts malicious SQL statements into a query, allowing them to execute commands the application shouldn’t perform. This type of injection leads to system compromise, unauthorized access to critical data, and database manipulation.
Cross-site scripting occurs when an attacker injects malicious scripts to gain access to sensitive user data and credentials, as well as hijack user sessions, deface websites, and redirect users to scam sites under the attacker’s control.
(для інфографіки: Injection Flaws: 6.7% of all discovered vulnerabilities in open-source projects and 10% in closed-source projects were injection vulnerabilities. Дані з https://medium.com/@zahirbdby/sql-injection-attacks-cost-companies-8-7m-heres-what-every-developer-must-know-ca614b7296b1)
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<H3> Insecure Deserialization
Insecure deserialization opens the door for attackers to execute malicious code, perform injection attacks, manipulate objects, and exploit privilege escalation. This vulnerability typically occurs when untrusted data is used to abuse the deserialization process logic. While serialization converts an object into a format that can be transmitted, stored, and reconstructed, deserialization is the reverse process, which can recreate the original object.
Therefore, the presence of a vulnerability can result in an application loading data without validating it, enabling hackers to perform remote code execution (RCE), denial of service (DoS), and authentication bypass.
(для інфографіки: Insecure deserialization is a rapidly growing threat, with reported issues increasing by 50% in 2024. Дані з https://www.cyserch.com/blog/Insecure-Deserialization-in-2024)
<H3> Third-Party and Supply-Chain Vulnerabilities
Common issues in web application security include the use of external components and solutions without proper testing. Third-party and supply-chain vulnerabilities can arise when organizations integrate APIs, frameworks, libraries, or components with known vulnerabilities into their applications. The core problem is that with this approach, developers rely on external code, meaning they lack full control over it, creating security gaps. Therefore, the use of outdated components or vulnerable elements, an attack on software vendors, or ignoring third-party module validation can lead to a situation where companies risk leaks, fines, and process downtime, while the vulnerability itself is beyond their direct control, so they depend on third-party vendors’ responses to incidents.
(для інфографіки: The year-over-year growth of malicious packages spiked by 188% in the second quarter of 2025. Дані з https://www.darkreading.com/application-security/malicious-open-source-packages-spike)
<H3> Data Storage and Transmission Weaknesses
Storage, transmission, and any interaction with data are critical aspects of fintech software applications. Interception and access of data (such as passwords, payment information, and sensitive user data) by hackers guarantees lawsuits, loss of customer trust, and fines for regulatory violations. The most common problems in data storage and transmission are often the result of a range of developer mistakes. These include storing passwords as plain text or with weak hashing, using outdated HTTP instead of HTTPS, integrating insecure APIs without authentication, applying weak encryption algorithms (MD5, SHA1), or storing unencrypted data, as well as ignoring protection for backups and temporary files.
(для інфографіки. Data Storage and Transmission Weaknesses: The global average cost of a data breach in 2025 is $4.44 million.
Дані з https://spac-alliance.org/library/imb-cost-of-a-data-breach-2025-report/)
<H2> Strategies for Addressing and Preventing Application Vulnerabilities
Effective strategies and solutions that developers can follow to minimize risks and address vulnerabilities include:
- Bounty Programs. This is an excellent approach, allowing collaboration with ethical hackers and bug hunters. With applications tested by white hat hackers, organizations gain insight into vulnerabilities and weaknesses in their software that could be exploited by attackers.
- Roles & Authorizations. It’s worth implementing the principle of least privilege to ensure users and applications have only the access required to perform actions. Role-based access control (RBAC) and permissions can help avoid problems with broken access control that allows access to unauthorized data or features.
- Secure Code. It’s crucial to thoroughly scan and audit your code to find vulnerabilities. Application security tools and methods such as static analysis (Static Application Security Testing), dynamic analysis (Dynamic Application Security Testing), and SCA (Software Composition Analysis) help identify vulnerabilities, security misconfigurations, flaws in logic and structure, gaps in open-source components, and other security risks.
- Penetration Testing. Pentesting simulates a real-world attack to identify vulnerabilities and assess the resilience of an application, providing insight into security gaps, database weaknesses, authentication system errors, identification failures, and more.
- Logging and Monitoring. Insufficient logging and monitoring lead to the system failing to record and monitor security-relevant events, allowing attackers to operate undetected. Organizations must implement continuous monitoring and detailed logging to detect and respond to suspicious activity (failed login attempts, unauthorized data access, etc.) in real time.
- Patch Management. Automated patching and updates should be included in your application vulnerability management. This allows you to promptly install the latest security fixes for your applications, libraries, and frameworks, avoiding situations where outdated software will be used as entry points for attackers.
- Failed Login Attempts Limit. Implement account lockouts after a set number of failed attempts to prevent unauthorized account access. It also makes sense to add CAPTCHA to differentiate between bots and users, and implement multi-factor authentication (MFA) for additional security.
<H2> Summary
Application vulnerabilities are entry points for attackers. When it comes to financial products, security is a key priority, as any gaps in the application code and architecture can lead to data breaches and ruin even the most innovative products.
Following the OVASP TOP 10 recommendations, conducting regular testing & threat modeling, as well as applying a DevOps approach to development, enables vulnerabilities to be identified and fixed early, before a product is released. This helps avoid costly fixes, fines, and loss of customer trust.
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5 Common Application Vulnerabilities We See in Fintech – Jappware
Discover 5 common application vulnerabilities in fintech, how they impact financial systems, and effective tactics to fix and prevent them.